enable user to manipulate a 3D model anchored to the floor

[nlsdvl]

Currently, the only way for users to control positioning of objects in AR is to use a 2D marker.
While the player supports AR anchoring to a floor or plane, the positioning on that surface is not adjustable by users.

The goal is to enable users to adjust position of the anchored 3D scene or node anywhere they wich.

TBD : This could be considered default player behaviour for anchors, or else it could be implemented taking into account the tracked floor or planes when the gltf scene specifies their use through the MPEG_anchor extension.

cc @Etiennefaivredarcier looking forward to your feedback.

[nlsdvl]

@Etiennefaivredarcier has proposed developer tools to support implementing this:

• Development tools rt-xr-gITFast#8
• Development tools rt-xr-content#25

The PRs are drafts meant to support demonstration of the player.

This is being integrated in a dedicated branch here for demonstration: https://github.com/5G-MAG/rt-xr-unity-player/tree/feature/anchored-object-manipulation

The implementation currently supports only one specific scene. With references to nodes in the scene hardcoded in the player.

See comments on the PR for details: 5G-MAG/rt-xr-gITFast#8 (review)

[nlsdvl]

This development was demonstrated at IBC however there is no clear milestone to integrate the changes in a release.

[nlsdvl]

No clear milestone for this. The development tools could help with the implementation when a gltf document contains the proper extensions (MPEG_anchor + MPEG_interactivity). The code sample shows how to move the asset, but there is no support for rotation.